Propeller-wheel.



No. 870,136. I PATBNTED NOV. 5, 1907.

R. w. SHAW. PROPELLER WHEEL.

APPLICATION FILED SEPT. 15 1906.

ROBERT WILLIAM SHAW, OF STAMFORD, CONNECTICUT.

PROrELLER-WEEEL.

Specification of Letters latent.

Patented Nov. 6, 1907.

Application filed September 15. 1906- Serial No. 384,723.

To all whom it may concern: I

Be it known that I, ROBERT WILLIAM SHAW, a citizen 4 of the United States, residing at Stamford, in the county of Fairfield and State of Connecticut, have invented a new and useful Propeller-Wheel, of which the following is a specification. Q

This invention relates to screw propellers for motor propelled boats and its object is to provide a device of this character made up ofsections which may be separately replaced in event ofbreakage. A still further object is to. provide propeller blades which are so shaped as to produce the maximum propelling force with the minimum power and which will not slip within the water.

Another object is to provide a propeller which is so constructed that it will not drag the stern of the boat downward but will insure the Boat remaining on an even keel throughout the operation of the propeller.

It is a well known fact that where flat propeller blades are employed there is considerable radial motion of the water produced thereby which results in a corresponding'diminution of power. Moreover this radial motion.

results in a downward pull 'upon the stern of the boat.

' The object of the present invention is to provide a propellerwhich will overcome all of these objections andwill neither produce radial movement of the water,

I nor drag the stern of the boat.

With the above and other objects in view the invention consists of certain novel features of constuction and combinations of parts which will :be hereinaftermore fully described and pointed out-in the claims.

In the accompanying drawings is shown the preferred form of the invention.

In said drawings: Figure 1 is a view partly in side elevation and partly in section of'a propeller constructed in aecordance with the present invention; and Fig. 2 is an end elevation thereof.

1 Referring to the figures by characters of reference, 1 is a propeller shaft upon which is arrange a hub 2 made up of similarly 'disposed sections adapdedto embrace the shaft, the ends of said. sections when boughttogether forming 'f'ru'sto conical extensions 3 which are ex ternally screw-threaded as shown at heand adapted to receive a frusto-conical nut 5 having 4 tapered, threaded opening therethrough. Extending from each section of the hub is a blade 6 of peculiar contourand the inner or base portion 7 of the blade is disposed diagwitnesses.

the concave face of theblade to constantly press against the water. It will beundorstood that both blades are of the same contour. After the blades have becomesembled by clamping the hub sections upon the shaft 1 the same are rotated in theusual manner and the Convex edges thereof first contact with the water and as the rear or working faces of the blade are concaved transversely it will be understood thatmhe water is positively propelled longitudinally'of the device and there is no radial motion and no slipping of the blades such as occurs where flat diagonally disposed blades are used. The curved blades such as herein described continually exert a pressure upon the water because of the constantly. changing contour thereof. A propeller such as herein described will not pull downward on the stern of the boat and therefore said boat will be made to more therein without departing from the spirit or sacrificing.

the advantages thereof, and I therefore reserve the right to make such changes as fairly fall within the scope of the claims.

What is claimed is 1.-A propeller comprising a sectional hub, means upon 'the ends of the sections for clamping the some upon a shaft, and outwardly inclined blades 'vdlsposed diagonally to the axis of the hub, each blade being concnvo-convex in crois section. y I

2. A propeller comprising a sectional hub, the ends of gaging the threaded ends of the sections for clamping the same upon a shaft, and outwardly inclined blades disposed diagonally to the axis of the hub, each blade being concavo-convex in section.

In testimony that I claim the toregoinga my own, I have hereto nfilxed my signature in -th e.presence of two RoBnIir WILLIAM snsw.

Witnesses:

CHARLES Eoonnis Cook, WrtnrAM-M. Ruuonn.

said sections being tnpered and screw-threaded, means en- 

